South leaving card game to sleep (3)
I believe the answer is:
nap
'sleep' is the definition.
('nap' can be a synonym of 'sleep')
'south leaving card game' is the wordplay.
'south leaving card' becomes 'na' (I can't justify this - if you can you should believe this answer much more).
'game' becomes 'p' (I have seen 'French game ' mean 'p' so perhaps 'game' could also mean 'p').
'na'+'p'='NAP'
'to' acts as a link.
Can you help me to learn more?
(Other definitions for nap that I've seen before include "A fuzzy surface texture" , "Sleep briefly" , "Sleep lightly" , "Racing tip that professes to be a certainty" , "Take forty winks" .)